Computer systems have become dramatically smaller and more portable. Personal computers and peripherals are small enough to sit on the desk at work. Smaller still are lap top computers and notebook computers. There are computer terminals which are small enough to be mounted in a vehicle such as a delivery truck. Still smaller are the hand held terminals typically used for their portability features where the user can carry the terminal in one hand and operate it with the other.
Many of today's computer systems can be hooked up to the Internet or the World Wide Web (WWW) being a part of the Internet. More and more of these devices draw at least part of their functionality from the Internet or WWW. A connection to the Internet or WWW can be established using Ethernet, Token Ring, or other wire based or fiber based schemes. Details and implementations of these schemes are well known in the art and are thus not addressed herein in detail.
Likewise, wireless ad-hoc connections schemes (e.g. body networks, radio frequency connections, or infrared connections) can be used to hook up a computer system to a network. Ad-hoc connections are required where devices move around, enter an area and exit the area. The term ad-hoc refers to the need for frequent network reorganization.
There are different wireless communications approaches known that have been developed and designed with an eye on the communication between peers or subsystems of such wireless ad-hoc networks. Typical examples are addressed in the following.
GTE Corporation has developed a short-range radio-frequency (RF) technique which is aimed at giving mobile devices such as cellular phones, pagers and handheld personal computers (PCs) a smart way to interact with one another. GTE's technique is tentatively named Body LAN (local area network). The original development of Body LAN was via a wired vest with which various devices were connected (hence the name Body LAN). This graduated to an RF connection a couple of years ago.
Xerox Corporation has developed a handheld computing device called PARC TAB. The PARC TAB is portable yet connected to the office workstation through base stations which have known locations. The PARC TAB base stations are placed around the building, and wired into a fixed wired network. A device can thus be connected through the PARC TAB base station to the Internet or WWW.
In an attempt to standardize data communication between disparate PC devices several companies, including Ericsson, IBM, Intel, Nokia, and Toshiba established a consortium to create a global standard for wireless RF-based connectivity between fixed, portable and mobile devices. There are many other adopter companies. The proposed standard comprises an architecture and protocol specifications ranging from the physical layer up to the application layer. Enabling seamless voice and data transmission via wireless, short-range radio, the Bluetooth technology will allow users to connect a wide range of devices easily and quickly, without the need for cables, expanding communications capabilities for mobile computers, mobile phones and other mobile devices. The Bluetooth operating environment is not yet fully defined, but there are expected to be similarities with the IrDA (Infrared Data Association) specification and the Advanced Infrared (AIr) specification. Other aspects that probably will find their way into Bluetooth might stem from the IEEE standard 802.11 and/or HIPERLAN, as promulgated by the European Telecommunications Standards Institute (ETSI).
Bluetooth radio technology provides a mechanism to form small private ad-hoc groupings of connected devices away from fixed network infrastructures. A link to a fixed network, such as the Internet or WWW might be provided. Further details can be found in Haartsen, Allen, Inouye, Joeressen, and Naghshineh, “Bluetooth: Vision, Goals, and Architecture” in the Mobile Computing and Communications Review, Vol. 1, No. 2. Mobile Computing and Communications Review is a publication of the ACM SIGMOBILE.
HomeRF (based on Shared Wireless Access Protocol (SWAP)) is another example of an operating environment which can be used to connect devices. A HomeRF Working Group was formed to provide the foundation for a broad range of interoperable consumer devices by establishing an open industry specification for wireless digital communication between PCs and consumer electronic devices anywhere in and around the home. The working group, which includes the leading companies from the personal computer, consumer electronics, peripherals, communications, software, and semiconductor industries, is developing a specification for wireless communications in the home called the SWAP. The HomeRF SWAP system is designed to carry both voice and data traffic and to interoperate with the Public Switched Telephone Network (PSTN) and the Internet or WWW; it operates in the 2400 MHz band and uses a digital frequency hopping spread spectrum radio. The SWAP technology was derived from extensions of existing cordless telephone (DECT) and wireless LAN technology to enable a new class of home cordless services. It supports both a time division multiple access (TDMA) service to provide delivery of interactive voice and other time-critical services, and a carrier sense multiple access/collision avoidance (CSMA/CA) service for delivery of high speed packet data. The SWAP system can operate either as an ad-hoc network or as a managed network under the control of a connection point. In an ad-hoc network, where only data communication is supported, all stations are equal and control of the network is distributed between stations. For time critical communications such as interactive voice, the connection point—which provides the gateway to the PSTN—is required to coordinate the system. Stations use the CSMA/CA to communicate with a connection point and other stations. Further details about HomeRF can be found at the Home Radio Frequency Working Group's web site http://www.homerf org. The SWAP specification 1.0 is incorporated by reference in its entirety.
It is a well known problem that computer systems, and in particular portable computers, are expensive and thus tempting to steal. There is also the likelihood that such devices get lost or that the owner or user forgets a device when traveling, for example.
There are a few protection mechanisms, like passwords, that are not widely used because of the added burden they impose on the user. An alternative to password-protection is to use a dedicated central registry on a network where devices periodically send “hello” messages together with their own address, in order to track stolen or lost devices. This alternative is vulnerable to firewalls because the “hello” messages going to the central registry can easily be intercepted by a firewall filter, since the central registry's well-known address must be carried in these “hello” messages.
It is an object of the present invention to provide a scheme enabling the discovery of a lost or stolen computer system.
It is another object of the present invention to provide systems enabling the discovery of a lost or stolen computer system.
Yet another object of the present invention is to provide a scheme or system enabling the discovery and subsequent tracking of a lost or stolen computer system.